There are many tablets that make phone calls. The US carriers choose not to sale them. But they will work on T-Mobile's and AT&T's networks. Asus makes the Fonepad. HP has the Slate 7 Voice. Sony's soon to be released Xperia X3 Tablet Compact will make phone calls.
Most of the tablets that Samsung has released have a variant that has telephony capability built in. Including the Tab 2, Tab 3, Tab 4, and Note series. The variants are distinquished by model number not by name. For example, the Samsung Note 8 has a model GT-N5100, which has telephone capability and SGH-i467, which doesn't, and GT-N5110, which is wifi only.
There is nothing to fear in buying international devices. Just make sure the frequency bands are compatible with AT&T and T-Mobile, and buy from a reputable source, like Amazon. I bought my Note 8 N5100 almost 2 years ago, and have been using it on AT&T ever since.